Energy analysis of drying basil (Ocimum basilicum) leaves in an active greenhouse solar dryer

摘要

The need for better utilization of solar greenhouses during summer in the hot climateconditions of Mexico led to the development of the concept of active greenhousesolar dryers. The objective of this research was energy analysis of an active greenhousesolar dryer for basil leaves drying. The effect of variable solar irradiation ondrying was accounted for by monitoring instantaneous effective diffusivity. Ourexperiments showed that the effective diffusivity of basil leaves increased with solarirradiation 100 times from 0.08 × 10~(-10) m~2/s in the morning to 8.11 × 10~(-10) m~2/sat the solar noon. The air temperature in the solar dryer was ranging from 42 to 48℃at the solar noon with solar irradiance of 806 W/m~2. The energy required for moistureevaporation of basil leaves depended on the air temperature, reaching337.6 kJ/mol just before solar noon. The amount of energy available in the solardryer at noon was 124.14 MJ, much exceeding the energy required for basil leavesdrying (16.94 MJ). The results of our study showed the feasibility of basil solar drying.The predictive model of basil drying in an active greenhouse solar dryer wasdeveloped.